Gregg walked and ran countless miles on Berkeley streets, then even more on a treadmill. With a slow-motion camera, they captured and duplicated the motion and forces that slowly break and pull even the strongest knots to failure.

So no, this is not a matter of human error. It's physics, with possible future applications that might even help us understand DNA.

You might be wondering how many millions of dollars this cost California taxpayers. Well, the researchers are already paid and they borrowed all of their equipment. Essentially, they did it on a shoestring.